1. Field of the Invention
The present invention relates to a substrate processing apparatus that subjects a substrate to processing.
2. Description of the Background Art
Substrate processing apparatuses have been conventionally used to perform various types of processes to substrates such as semiconductor wafers, glass substrates for photomasks, glass substrates for liquid crystal displays, glass substrates for optical disks or the like.
For example, the substrate processing apparatus including a reversing unit that reverses a top surface and a back surface of the substrate is described in JP 2004-146708 A. In such a substrate processing apparatus, a center robot (transport unit) that transports the substrate is arranged in substantially the center of a rectangular processing section.
In the processing section, a plurality of (four, for example) back surface cleaning units that perform cleaning processes to the back surfaces of the substrates, respectively, are arranged so as to surround the center robot. In addition, the reversing unit is arranged in a position where the center robot can access in the processing section.
An indexer section including a plurality of storing containers that store the substrates is provided on one end of the processing section. A substrate transport robot that takes the substrate before processing out of the above-mentioned storing container or stores the substrate after the processing in the above-mentioned storing container is provided in this indexer section.
In the above-described configuration, the substrate transport robot takes the substrate before the processing out of any of the storing containers and transfers the substrate to the center robot while receiving the substrate after the processing from the center robot and storing the substrate in the storing container.
The center robot receives the substrate before the processing from the substrate transport robot and subsequently transfers the received substrate to the reversing unit. The reversing unit reverses the substrate received from the center robot so that the top surface thereof is directed downward. Then, the center robot receives the substrate reversed by the reversing unit and carries the substrate into any of the back surface cleaning units.
Next, when the processing is finished in any of the back surface cleaning units described above, the center robot carries the substrate out of the back surface cleaning unit and again transfers the substrate to the reversing unit. The reversing unit reverses the substrate that has been subjected to the processing in the back surface cleaning unit so that the top surface thereof is directed upward.
The center robot subsequently receives the substrate reversed by the reversing unit and transfers it to the substrate transport robot. The substrate transport robot receives the substrate after the processing from the center robot and stores it in the storing container.
In the above-described conventional substrate processing apparatus, however, an operation of the center robot becomes complicated because the number of transporting processes of the substrate is increased. In recent years, cleaning processing to an outer peripheral surface of the substrate has also been desired. If an end surface cleaning unit that performs the cleaning processing to the outer peripheral surface of the substrate is provided in addition to the foregoing configuration, the operation of the center robot becomes even more complicated. In this case, it becomes difficult to efficiently transport a plurality of substrates, and the throughput in substrate processing is significantly decreased.
Furthermore, there is the substrate processing apparatus including a top surface processing unit that performs the processing to the top surface of the substrate, the back surface processing unit that performs the processing to the back surface of the substrate and the reversing unit that reverses the top surface and the back surface of the substrate. In such a substrate processing apparatus, the center robot that transports the substrate is arranged at substantially the center of the rectangular processing section.
In the processing section, the top surface processing unit and the back surface processing unit are arranged so as to surround the center robot. In addition, the reversing unit is arranged in a position where the center robot can access in the processing section.
An indexer section including the plurality of storing containers that store the substrates is provided on one end of the processing section. The substrate transport robot that takes the substrate before the processing out of the above-mentioned storing container or stores the substrate after the processing in the above-mentioned storing container is provided in this indexer section.
In the above-described configuration, the substrate transport robot takes the substrate before the processing out of any of the storing containers and transfers it to the center robot while receiving the substrate after the processing from the center robot and storing it in the storing container.
The center robot receives the substrate before the processing from the substrate transport robot and subsequently carries the received substrate into the top surface cleaning unit. After the processing is finished in the top surface cleaning unit, the center robot carries the substrate out of the top surface cleaning unit, and then transfers it to the reversing unit. The reversing unit reverses the substrate received from the center robot so that the top surface thereof is directed downward. Then, the center robot receives the substrate reversed by the reversing unit and carries the substrate into the back surface cleaning units.
When the processing is finished in the back surface cleaning unit, the center robot carries the substrate out of the back surface cleaning unit and again transfers it to the reversing unit. The reversing unit reverses the substrate subjected to the processing in the back surface cleaning unit so that the top surface thereof is directed upward.
The center robot subsequently receives the substrate reversed by the reversing unit and transfers it to the substrate transport robot. The substrate transport robot receives the substrate after the processing from the center robot and stores it in the storing container.
As described above, the substrate is transported among the top surface processing unit, the back surface processing unit and the reversing unit by the single center robot. Accordingly, the number of the transporting processes of the substrate is increased, so that the operation of the center robot becomes complicated. This makes it difficult to efficiently transport the plurality of substrates, and reduces the throughput of the substrate processing.